IMO Shortlist 1987 problem 21
Dodao/la: arhiva2. travnja 2012.
In an acute-angled triangle
the interior bisector of angle
and meets the circumcircle of
perpendiculars are drawn to
, with feet
respectively. Prove that the quadrilateral
and the triangle
have equal areas.(IMO Problem 2)
Proposed by Soviet Union.
Izvor: Međunarodna matematička olimpijada, shortlist 1987